13 degrees advance?

[A bear in his natural habitat <burden@rhett.ENET.dec.com>]

I finally broke down and bought an adjustable timing light and played with the
'71 Squareback (4 speed, f/i).  It has been stumbling a bit and seems to be a
little down on power.  I checked the points and they are fine.  I plugged in
the timing light and at idle it comes out at 0 degrees.  With the engine
revving (2000 rpm maybe? - no tach) it appears to be advancing only to 13
degrees.  If I disconnect the vacuum line to the advance unit it does not
advance at all, which is to be expected, but I wanted to check it anyway.

I can't find my Muir manual so I'm not sure what the proper advance should be
under throttle.

If it's not advancing enough, what's the next thing to check?

Dave

ps - sometimes it's nice to deal with diesels and my old Studebakers which have
manual advance from the steering wheel...:-)